Hi Dutch
Welcome to the world of orchids
The basic rule is not to divide into less than three bulbs. Oncidiums like to be crowded so my personal choice would be to pot them together in a pot that will not be oversized for them.
In my experience, oncidium bulbs are usually pretty wrinkled. I am just starting to see some improvement in my oncidiums...for some reason, they've been giving me a hard time. I guess they've decided to play nice
